Field of the Invention
The field of the invention relates to portable and fixed electric vehicle supply equipment (EVSE).
Description of the Related Art
A charging station or Electric Vehicle Supply Equipment (EVSE) is used to provide high levels of power to electric vehicles (EVs) safely by only energizing the EVSE's power cable and supplying power to the EV when the EVSE detects that it is connected to an EV. In addition to the wires for carrying the electricity from the EVSE to the EV, the EVSE's power cable has a pilot line, which when the EVSE is plugged into an EV, connects the EVSE's and the EV's control systems and allows communication. The EVSE will only supply power when the EV is connected to the EVSE, and the EVSE will automatically shut off the power to the EV when the EVSE is disconnected from the EV.
When installed in a public location, turning the EVSE's power on may require an external authorization from a home office. This external authorization allows the EVSE's owner/operator to control who may use the EVSE, how long it may be used, as well as to obtain payment for its use. One example of such an EVSE system is shown in FIG. 1 (prior art), where an EVSE system 100 includes a connector 105, such as a J1772 compliant connector for connecting to an EV 145, a power cable 110 for communicating power and communications to the EV 145, a power switch or relay 115 to switch AC power between a utility power supply 120 and the connector 105, an EVSE control system 125 for selectively switching on/off the power switch 115, a system box 130 encompassing the power switch 115 and EVSE control system 125, a control interface 135 to accept input from a user, a pilot line 140 for communication between a connected EV 145 and the EVSE control system 125, a user activation card 150, a wireless communication system 155 for the EVSE control system 125 to communicate back to an EVSE home office 160 through a wireless connection 165 that includes a cell tower 167, and a wired communication system 170 for the EVSE control system 125 to communicate back to an EVSE home office 160 without a wireless connection 165. Upon connection to the EV 145, the EVSE system 100 may be activated by either using the control interface 135, such as a keypad or a touch screen and/or via the activation card 150, such as an RFID card. The interface 135 is connected to the control system 125 which can activate the power switch 115 to switch power to the EV 145. When authorization is required, the EVSE control system 125 will use the wired communication 170 to contact a home office 160 via a two-way communication system such as a telephone connection or via an internet connection. Alternatively, the control system 125 can use the wireless system 155 to contact the home office 160, where the wireless system 155 is a cell phone system.
Another activation method is for the user to use his/her cell phone 175 to either call the home office 160 or, in the case of a smart phone, to wirelessly connect to the home office 160 via the internet (typically using a phone number or website set forth on the system box 130). Upon authorization (and typically payment), the home office 160 will then signal the EVSE control system 125, via either the wired 170 or wireless 165 connections, to activate the charging of the EV.
As can be seen, regardless of the means (cell phone or control interface) that the user uses to interface with the EVSE system 100, to obtain authorization to charge the EV requires that either the wired 170 or wireless 155 connections be in place and functioning. Such wired or wireless connection can be expensive and time consuming to install and operate and their operations may be limited by bandwidth restrictions.